Whether and When Superhydrophobic/Superoleophobic Surfaces Are Fingerprint Repellent

Chengjiao Wu; Yue Fan; Hongxin Wang; Juan Li; Yuxi Chen; Yingke Wang; Lin Liu; Lidan Zhou; Shilin Huang; Xuelin Tian

doi:10.34133/2022/9850316

Whether and When Superhydrophobic/Superoleophobic Surfaces Are Fingerprint Repellent

Research (Wash D C). 2022 Sep 23:2022:9850316. doi: 10.34133/2022/9850316. eCollection 2022.

Authors

Chengjiao Wu^{1

2}, Yue Fan^{1

2}, Hongxin Wang^{1

2}, Juan Li^{1

2

3}, Yuxi Chen^{1

2}, Yingke Wang^{1

2}, Lin Liu², Lidan Zhou², Shilin Huang^{1

2}, Xuelin Tian^{1

2}

Affiliations

¹ Key Laboratory for Polymeric Composite & Functional Materials of Ministry of Education, Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices, School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China.
² State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510006, China.
³ School of Traditional Chinese Medicine Resources, Guangdong Pharmaceutical University, Guangzhou 510006, China.

Abstract

Driven by the ever-increasing demand for fingerprint-resistant techniques in modern society, numerous researches have proposed to develop innovative antifingerprint coatings based on superhydrophobic/superoleophobic surface design. However, whether superhydrophobic/superoleophobic surfaces have favorable repellency to the microscopic fingerprint is in fact an open question. Here, we establish a reliable method that enables evaluating the antifingerprint capability of various surfaces in a quantitative way. We show that superhydrophobicity is irrelevant with fingerprint repellency. Regarding superoleophobic surfaces, two distinct wetting states of microscopic fingerprint residues, i.e., the "repellent" and the "collapsed" states, are revealed. Only in the "repellent" state, in which the fingerprint residues remain atop surface textures upon being pressed, superoleophobic surfaces can bring about favorable antifingerprint repellency, which correlates positively with their receding contact angles. A finger-deformation-dependent intrusion mechanism is proposed to account for the formation of different fingerprint wetting states. Our findings offer important insights into the mechanism of fingerprint repellency and will help the design of high-performance antifingerprint surfaces for diverse applications.